[SOLVED] ULN2803 with PIC microcontroller to control loads

[papunblg]

This project may help a new hobbyist to understand how to interface ULN2803 with PIC micro to control loads up to 500mA with schematic, picture and video.
Please refer to ULN2803 datasheet at http://www.datasheetcatalog.org/datasheets/90/366828_DS.pdf
Here the given code will drive 8 lines of LEDs to produce few fascinating designs.



;;;;;;;;;;;;;;;;;;;;;;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;Below is the code file;;;;;;;;;;;;;;;;;;;

	list	p=16F84A
	#include	<p16F84A.inc>
	__CONFIG	_CP_OFF & _WDT_OFF & _PWRTE_ON & _XT_OSC
	ERRORLEVEL -302

	

COUNT2		EQU		09H
COUNT1		EQU		08H
		

		PAGESEL	START
		GOTO	START
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
LTOR	MACRO	BY_N
			[INDENT]VARIABLE	I[/INDENT]
I=0
		[INDENT]WHILE I<BY_N
		CALL	ALLOFB
		CALL 	DELAY
		CALL	B0
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		CALL	ALLOFB
		CALL	DELAY[/INDENT]
I+=1
		[INDENT]ENDW
		ENDM[/INDENT]
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;  ;;;;;;;;;;;;;
RTOL	MACRO	BY_N
			[INDENT]VARIABLE	I[/INDENT]
I=0
		[INDENT]WHILE I<BY_N
		CALL	ALLOFB
		CALL 	DELAY
		CALL	B7
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		CALL	ALLOFB
		CALL	DELAY[/INDENT]
I+=1
		[INDENT]ENDW
		ENDM[/INDENT]
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;  ;;;;;;;;;;;;;
RTOL2	MACRO	BY_N
			[INDENT]VARIABLE	I[/INDENT]I=0
		[INDENT]WHILE I<BY_N
		CALL	ALLOFB
		CALL 	DELAY
		MOVLW	B'11000000' ;RB7
		MOVWF	PORTB
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		CALL	ALLOFB[/INDENT]
		[INDENT]CALL	DELAY[/INDENT]I+=1
		[INDENT]ENDW
		ENDM[/INDENT]
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;  ;;;;;;;;;;;

LTOR2	MACRO	BY_N
			[INDENT]VARIABLE	I[/INDENT]
I=0
		[INDENT]WHILE I<BY_N
		CALL	ALLOFB
		CALL 	DELAY
		MOVLW	B'00000011' ;RB1
		MOVWF	PORTB
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		CALL	ALLOFB
		CALL	DELAY[/INDENT]
I+=1
		[INDENT]ENDW
		ENDM[/INDENT]
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;  ;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;  ;;;;;;;;;;;;;
RTOL3	MACRO	BY_N
			[INDENT]VARIABLE	I[/INDENT]
I=0
		[INDENT]WHILE I<BY_N
		CALL	ALLOFB
		CALL 	DELAY
		MOVLW	B'11100000' ;RB7
		MOVWF	PORTB
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		CALL	ALLOFB
		CALL	DELAY[/INDENT]
I+=1
		[INDENT]ENDW
		ENDM[/INDENT]
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;  ;;;;;;;;;;;

LTOR3	MACRO	BY_N
			[INDENT]VARIABLE	I[/INDENT]
I=0
		[INDENT]WHILE I<BY_N
		CALL	ALLOFB
		CALL 	DELAY
		MOVLW	B'00000111' ;RB1
		MOVWF	PORTB
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		RLF		PORTB,1
		CALL 	DELAY
		CALL	ALLOFB
		CALL	DELAY[/INDENT]
I+=1
		[INDENT]ENDW
		ENDM[/INDENT]
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;  ;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;  ;;;;;;;;;;;

LTOR1B	MACRO	BY_N
			[INDENT]VARIABLE	I[/INDENT]
I=0
		[INDENT]WHILE I<BY_N
		CALL	ALLONB
		CALL 	DELAY
		MOVLW	B'11111110' ;RB0
		MOVWF	PORTB
		CALL 	DELAY
		MOVLW	B'11111101' ;RB1
		MOVWF	PORTB
		CALL 	DELAY
		MOVLW	B'11111011' ;RB2
		MOVWF	PORTB
		CALL 	DELAY
		MOVLW	B'11110111' ;RB3
		MOVWF	PORTB
		CALL 	DELAY
		MOVLW	B'11101111' ;RB4
		MOVWF	PORTB
		CALL 	DELAY
		MOVLW	B'11011111' ;RB5
		MOVWF	PORTB
		CALL 	DELAY
		MOVLW	B'10111111' ;RB6
		MOVWF	PORTB
		CALL 	DELAY
		MOVLW	B'01111111' ;RB7
		MOVWF	PORTB
		CALL 	DELAY
		CALL	ALLONB
		CALL	DELAY[/INDENT]I+=1
		[INDENT]ENDW
		ENDM[/INDENT]
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;  ;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;  ;;;;;;;;;;;;;
RTOL1B	MACRO	BY_N
			[INDENT]VARIABLE	I[/INDENT]
I=0
		[INDENT]WHILE I<BY_N
		CALL	ALLOFB
		CALL 	DELAY
		MOVLW	B'01111111' ;RB0
		MOVWF	PORTB
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		RRF		PORTB,1
		CALL 	DELAY
		CALL	ALLOFB
		CALL	DELAY[/INDENT]I+=1
		[INDENT]ENDW
		ENDM[/INDENT]
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;  ;;;;;;;;;;;;;
DELAY	
LOOP1	[INDENT]decfsz COUNT1,1
		goto LOOP1 
		decfsz COUNT2,1
		goto LOOP1
		RETURN[/INDENT]
ALLOFB
		[INDENT]MOVLW	B'00000000'
		MOVWF	PORTB
		RETURN[/INDENT]ALLONB
		[INDENT]MOVLW	B'11111111'
		MOVWF	PORTB
		RETURN[/INDENT]
B7		[INDENT]MOVLW	B'10000000' ;RB7
		MOVWF	PORTB
		CALL 	DELAY
		RETURN[/INDENT]


B0		[INDENT]MOVLW	B'00000001' ;RB1
		MOVWF	PORTB
		CALL 	DELAY
		RETURN[/INDENT]

START	
		[INDENT]BSF		STATUS,RP0
		MOVLW	B'00000000'
		MOVWF	TRISB
		BCF		STATUS,RP0
		LTOR	6
		RTOL	6
		RTOL2	6
		CALL	ALLONB
		CALL 	DELAY
		CALL	ALLOFB
		CALL 	DELAY
		CALL	ALLONB
		CALL 	DELAY
		CALL	ALLOFB
		CALL 	DELAY
		LTOR1B	6
		CALL 	DELAY
		CALL 	DELAY
		GOTO	START
		
		END[/INDENT]

 

[alexan_e]

Please note that the current that each output can give depends on the number of outputs used and the duty cycle, unfortunately I had to search 5 datasheets to find that graph because it is not included in all of them.
I have found it in www.rentron.com/Files/uln2803.pdf (Allegro)



An alternative for 1.5A is ULN2065, ULN2069


Alex

 

[papunblg]

Once again very very important note from Mr. Alex. Always give another dimension. Thanks.